Direction: A horizontal circular curve with a centre line radius of 200 m is provided on a 2-lane, 2-way SH section. The width of the 2-lane road is 7.0 m. Design speed for this section is 80 km per hour. The brake reaction time is 2.4 s, and the coefficients of friction in longitudinal and lateral directions are 0.355 and 0.15, respectively.
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The set-back distance from the centre line of the inner lane is
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- 7.93 m
- 8.10 m
- 9.60 m
- 9.77 m
Correct Option: C
Setback distance from centre line = R – R cos α/2
| α = | ⇒ | = | = | × | degree | |||||
| R | 2 | 2R | 2R | π |
| ∴ Setback distance = R - R.cos | ||
| 2πR |
| = 200 - 200 cos |  |  | = 9.6 m | |
| 2π × 200 |
